android studio使用kotlin的gridlayout的布局实现计算器功能

好的，以下是实现计算器功能的步骤：

1. 在 Android Studio 中创建一个新的 Kotlin 项目。
2. 打开 activity_main.xml 文件，在根布局中添加一个 GridLayout 控件，并设置它的列数为 4。

<GridLayout
    android:id="@+id/gridLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:columnCount="4">
</GridLayout>

3. 在 GridLayout 中添加按钮，分别代表数字、运算符和其他功能，例如清除、删除和等于号。

<Button
    android:id="@+id/btn_clear"
    android:text="C"
    android:layout_column="0"
    android:layout_row="0"
    android:layout_columnSpan="2" />

<Button
    android:id="@+id/btn_delete"
    android:text="DEL"
    android:layout_column="2"
    android:layout_row="0" />

<Button
    android:id="@+id/btn_divide"
    android:text="/"
    android:layout_column="3"
    android:layout_row="0" />

<Button
    android:id="@+id/btn_7"
    android:text="7"
    android:layout_column="0"
    android:layout_row="1" />

<Button
    android:id="@+id/btn_8"
    android:text="8"
    android:layout_column="1"
    android:layout_row="1" />

<Button
    android:id="@+id/btn_9"
    android:text="9"
    android:layout_column="2"
    android:layout_row="1" />

<Button
    android:id="@+id/btn_multiply"
    android:text="*"
    android:layout_column="3"
    android:layout_row="1" />

<Button
    android:id="@+id/btn_4"
    android:text="4"
    android:layout_column="0"
    android:layout_row="2" />

<Button
    android:id="@+id/btn_5"
    android:text="5"
    android:layout_column="1"
    android:layout_row="2" />

<Button
    android:id="@+id/btn_6"
    android:text="6"
    android:layout_column="2"
    android:layout_row="2" />

<Button
    android:id="@+id/btn_minus"
    android:text="-"
    android:layout_column="3"
    android:layout_row="2" />

<Button
    android:id="@+id/btn_1"
    android:text="1"
    android:layout_column="0"
    android:layout_row="3" />

<Button
    android:id="@+id/btn_2"
    android:text="2"
    android:layout_column="1"
    android:layout_row="3" />

<Button
    android:id="@+id/btn_3"
    android:text="3"
    android:layout_column="2"
    android:layout_row="3" />

<Button
    android:id="@+id/btn_plus"
    android:text="+"
    android:layout_column="3"
    android:layout_row="3" />

<Button
    android:id="@+id/btn_0"
    android:text="0"
    android:layout_column="0"
    android:layout_row="4"
    android:layout_columnSpan="2" />

<Button
    android:id="@+id/btn_dot"
    android:text="."
    android:layout_column="2"
    android:layout_row="4" />

<Button
    android:id="@+id/btn_equal"
    android:text="="
    android:layout_column="3"
    android:layout_row="4" />

4. 在 MainActivity.kt 文件中，设置按钮的点击事件，并实现计算器的逻辑。

import android.os.Bundle
import android.view.View
import android.widget.Button
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.children
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity(), View.OnClickListener {

    private var input = ""
    private var result = ""

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        btn_clear.setOnClickListener(this)
        btn_delete.setOnClickListener(this)
        btn_divide.setOnClickListener(this)
        btn_multiply.setOnClickListener(this)
        btn_minus.setOnClickListener(this)
        btn_plus.setOnClickListener(this)
        btn_dot.setOnClickListener(this)
        btn_equal.setOnClickListener(this)

        gridLayout.children.forEach {
            if (it is Button) {
                it.setOnClickListener(this)
            }
        }
    }

    override fun onClick(view: View?) {
        when (view?.id) {
            R.id.btn_clear -> {
                input = ""
                result = ""
                updateResult()
            }
            R.id.btn_delete -> {
                if (input.isNotEmpty()) {
                    input = input.substring(0, input.length - 1)
                    updateResult()
                }
            }
            R.id.btn_divide -> {
                handleOperator("/")
            }
            R.id.btn_multiply -> {
                handleOperator("*")
            }
            R.id.btn_minus -> {
                handleOperator("-")
            }
            R.id.btn_plus -> {
                handleOperator("+")
            }
            R.id.btn_dot -> {
                if (input.isNotEmpty() && !input.contains(".")) {
                    input += "."
                    updateResult()
                }
            }
            R.id.btn_equal -> {
                if (input.isNotEmpty() && result.isNotEmpty()) {
                    val expression = "$result$input"
                    val answer = Expression(expression).calculate()
                    result = answer.toString()
                    input = ""
                    updateResult()
                }
            }
            else -> {
                val digit = (view as Button).text.toString()
                input += digit
                updateResult()
            }
        }
    }

    private fun handleOperator(operator: String) {
        if (input.isNotEmpty()) {
            result = if (result.isNotEmpty()) {
                val expression = "$result$input"
                val answer = Expression(expression).calculate()
                input = ""
                answer.toString()
            } else {
                input
            }
            input = ""
            result += operator
            updateResult()
        }
    }

    private fun updateResult() {
        tv_result.text = if (result.isNotEmpty()) {
            "$result$input"
        } else {
            input
        }
    }
}

5. 在 MainActivity.kt 文件中，添加一个名为 "Expression" 的类，用于计算表达式的值。

import java.util.*

class Expression(val expression: String) {

    private val operators: Stack<String> = Stack()
    private val operands: Stack<Double> = Stack()

    fun calculate(): Double {
        val tokens = expression.split(" ")

        tokens.forEach { token ->
            when {
                isNumber(token) -> {
                    operands.push(token.toDouble())
                }
                isOperator(token) -> {
                    while (operators.isNotEmpty() && precedence(operators.peek()) >= precedence(token)) {
                        val operator = operators.pop()
                        val operand2 = operands.pop()
                        val operand1 = operands.pop()
                        operands.push(applyOperator(operator, operand1, operand2))
                    }
                    operators.push(token)
                }
                token == "(" -> {
                    operators.push(token)
                }
                token == ")" -> {
                    while (operators.peek() != "(") {
                        val operator = operators.pop()
                        val operand2 = operands.pop()
                        val operand1 = operands.pop()
                        operands.push(applyOperator(operator, operand1, operand2))
                    }
                    operators.pop()
                }
            }
        }

        while (operators.isNotEmpty()) {
            val operator = operators.pop()
            val operand2 = operands.pop()
            val operand1 = operands.pop()
            operands.push(applyOperator(operator, operand1, operand2))
        }

        return operands.pop()
    }

    private fun isNumber(token: String): Boolean {
        return try {
            token.toDouble()
            true
        } catch (e: NumberFormatException) {
            false
        }
    }

    private fun isOperator(token: String): Boolean {
        return token == "+" || token == "-" || token == "*" || token == "/"
    }

    private fun precedence(token: String): Int {
        return when (token) {
            "+", "-" -> 1
            "*", "/" -> 2
            else -> 0
        }
    }

    private fun applyOperator(operator: String, operand1: Double, operand2: Double): Double {
        return when (operator) {
            "+" -> operand1 + operand2
            "-" -> operand1 - operand2
            "*" -> operand1 * operand2
            "/" -> operand1 / operand2
            else -> 0.0
        }
    }
}

以上就是使用 Kotlin 和 GridLayout 布局实现计算器功能的步骤。